The adventus Saxonum is a crucial event in English protohistory. Scholars from a range of disciplines dispute the scale and demographic profile of the purported colonizing population. The 5th–7th century burial ground at West Heslerton, North Yorkshire, is one of the few Anglian cemeteries where an associated settlement site has been identified and subjected to extensive multidisciplinary postexcavation study. Skeletal and grave good evidence has been used to indicate the presence of Scandinavian settlers. A small, preliminary study using lead and strontium isotope analysis of tooth enamel, mineralized in early childhood, from Neolithic/Early Bronze Age (n = 8), Iron Age (n = 2), and Early Anglo-Saxon (n = 32) skeletons, was carried out to directly investigate this hypothesis. Results suggest that lead provides dissimilar types of information in different time periods. In post-Roman England, it appears to reflect the level of exposure to circulated anthropogenic rather than natural geological lead, thus being a cultural rather than geographical marker. Consequently, only strontium provides mobility evidence among the Anglian population, whereas both isotope systems do so in pre-Roman periods. Strontium data imply the presence of two groups: one of “local” and one of “nonlocal” origin, but more work is required to define the limits of local variation and identify immigrants with confidence. Correlations with traditional archaeological evidence are inconclusive. While the majority of juveniles and prehistoric individuals fall within the “local” group, both groups contain juveniles, and adults of both sexes. There is thus no clear support for the exclusively male, military-elite invasion model at this site. Am J Phys Anthropol 126:123–138, 2005. © 2004 Wiley-Liss, Inc.